//SamXIAO
#include <bits/stdc++.h>
using namespace std;
#define szCNT_OF(x) (sizeof(x) / sizeof(x[0]))
#define MAX_LEN 502  // 10 * 1000 * 1000 + 86

int dat[MAX_LEN];

//bool cmp(string x1, string x2) { return x1 < x2; }
void work1() {
   int n;
   int cnt = 0;
   scanf("%d", &n);
   for (int i = 0; i < n; i++) {
      int x;
      scanf("%d", &x);
      dat[x + 50]++;
   }

   n = n / 2 + 1;
   for (int i = 0; i < 102; i++) {
      if (dat[i] >= n) {
         printf("%d", i - 50);
         return;
      }
   }
   printf("no");
}

int main() {
   work1();
   return 0;
}
